Implement cancellation for the Future interface.

stub/src/main/java/io/grpc/stub/Calls.java

@@ -33,9 +33,9 @@ package io.grpc.stub;
 
 import com.google.common.base.Preconditions;
 import com.google.common.base.Throwables;
+import com.google.common.util.concurrent.AbstractFuture;
 import com.google.common.util.concurrent.ExecutionError;
 import com.google.common.util.concurrent.ListenableFuture;
-import com.google.common.util.concurrent.SettableFuture;
 import com.google.common.util.concurrent.UncheckedExecutionException;
 
 import io.grpc.Call;
@@ -45,13 +45,15 @@ import io.grpc.Status;
 
 import java.util.Iterator;
 import java.util.NoSuchElementException;
+import java.util.concurrent.ArrayBlockingQueue;
 import java.util.concurrent.BlockingQueue;
 import java.util.concurrent.CancellationException;
 import java.util.concurrent.ExecutionException;
 import java.util.concurrent.Future;
-import java.util.concurrent.ArrayBlockingQueue;
 import java.util.concurrent.TimeUnit;
 
+import javax.annotation.Nullable;
+
 /**
  * Utility functions for processing different call idioms. We have one-to-one correspondence
  * between utilities in this class and the potential signatures in a generated stub class so
@@ -81,7 +83,7 @@ public class Calls {
   public static <ReqT, RespT> ListenableFuture<RespT> unaryFutureCall(
       Call<ReqT, RespT> call,
       ReqT param) {
-    SettableFuture<RespT> responseFuture = SettableFuture.create();
+    GrpcFuture<RespT> responseFuture = new GrpcFuture<RespT>(call);
     asyncServerStreamingCall(call, param, new UnaryStreamToFuture<RespT>(responseFuture));
     return responseFuture;
   }
@@ -188,7 +190,7 @@ public class Calls {
   public static <ReqT, RespT> RespT blockingClientStreamingCall(
       Call<ReqT, RespT> call,
       Iterator<ReqT> clientStream) {
-    SettableFuture<RespT> responseFuture = SettableFuture.create();
+    GrpcFuture<RespT> responseFuture = new GrpcFuture<RespT>(call);
     call.start(new UnaryStreamToFuture<RespT>(responseFuture), new Metadata.Headers());
     try {
       while (clientStream.hasNext()) {
@@ -285,13 +287,13 @@ public class Calls {
   }
 
   /**
-   * Complete a SettableFuture using {@link StreamObserver} events.
+   * Complete a GrpcFuture using {@link StreamObserver} events.
    */
   private static class UnaryStreamToFuture<RespT> extends Call.Listener<RespT> {
-    private final SettableFuture<RespT> responseFuture;
+    private final GrpcFuture<RespT> responseFuture;
     private RespT value;
 
-    public UnaryStreamToFuture(SettableFuture<RespT> responseFuture) {
+    public UnaryStreamToFuture(GrpcFuture<RespT> responseFuture) {
       this.responseFuture = responseFuture;
     }
 
@@ -324,6 +326,29 @@ public class Calls {
     }
   }
 
+  private static class GrpcFuture<RespT> extends AbstractFuture<RespT> {
+    private final Call call;
+
+    GrpcFuture(Call call) {
+      this.call = call;
+    }
+
+    @Override
+    protected void interruptTask() {
+      call.cancel();
+    }
+
+    @Override
+    protected boolean set(@Nullable RespT resp) {
+      return super.set(resp);
+    }
+
+    @Override
+    protected boolean setException(Throwable throwable) {
+      return super.setException(throwable);
+    }
+  }
+
   /**
    * Convert events on a {@link io.grpc.Call.Listener} into a blocking
    * {@link Iterator}.

stub/src/test/java/io/grpc/stub/CallsTest.java

@@ -0,0 +1,117 @@
+/*
+ * Copyright 2015, Google Inc. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *    * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *    * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *
+ *    * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+package io.grpc.stub;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.fail;
+import static org.mockito.Mockito.any;
+import static org.mockito.Mockito.verify;
+
+import com.google.common.util.concurrent.ListenableFuture;
+
+import io.grpc.Call;
+import io.grpc.Metadata;
+import io.grpc.Status;
+
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.junit.runners.JUnit4;
+import org.mockito.ArgumentCaptor;
+import org.mockito.Mock;
+import org.mockito.MockitoAnnotations;
+
+import java.util.concurrent.CancellationException;
+import java.util.concurrent.ExecutionException;
+
+/**
+ * Unit tests for {@link Calls}.
+ */
+@RunWith(JUnit4.class)
+public class CallsTest {
+
+  @Mock private Call<Integer, String> call;
+
+  @Before public void setUp() {
+    MockitoAnnotations.initMocks(this);
+  }
+
+  @SuppressWarnings("unchecked")
+  @Test public void unaryFutureCallSuccess() throws Exception {
+    Integer req = 2;
+    ListenableFuture<String> future = Calls.unaryFutureCall(call, req);
+    ArgumentCaptor<Call.Listener> listenerCaptor = ArgumentCaptor.forClass(Call.Listener.class);
+    verify(call).start(listenerCaptor.capture(), any(Metadata.Headers.class));
+    Call.Listener<String> listener = listenerCaptor.getValue();
+    verify(call).sendPayload(req);
+    verify(call).halfClose();
+    listener.onPayload("bar");
+    listener.onClose(Status.OK, new Metadata.Trailers());
+    assertEquals("bar", future.get());
+  }
+
+  @SuppressWarnings("unchecked")
+  @Test public void unaryFutureCallFailed() throws Exception {
+    Integer req = 2;
+    ListenableFuture<String> future = Calls.unaryFutureCall(call, req);
+    ArgumentCaptor<Call.Listener> listenerCaptor = ArgumentCaptor.forClass(Call.Listener.class);
+    verify(call).start(listenerCaptor.capture(), any(Metadata.Headers.class));
+    Call.Listener<String> listener = listenerCaptor.getValue();
+    listener.onClose(Status.INVALID_ARGUMENT, new Metadata.Trailers());
+    try {
+      future.get();
+      fail("Should fail");
+    } catch (ExecutionException e) {
+      Status status = Status.fromThrowable(e.getCause());
+      assertEquals(Status.INVALID_ARGUMENT, status);
+    }
+  }
+
+  @SuppressWarnings("unchecked")
+  @Test public void unaryFutureCallCancelled() throws Exception {
+    Integer req = 2;
+    ListenableFuture<String> future = Calls.unaryFutureCall(call, req);
+    ArgumentCaptor<Call.Listener> listenerCaptor = ArgumentCaptor.forClass(Call.Listener.class);
+    verify(call).start(listenerCaptor.capture(), any(Metadata.Headers.class));
+    Call.Listener<String> listener = listenerCaptor.getValue();
+    future.cancel(true);
+    verify(call).cancel();
+    listener.onPayload("bar");
+    listener.onClose(Status.OK, new Metadata.Trailers());
+    try {
+      future.get();
+      fail("Should fail");
+    } catch (CancellationException e) {
+      // Exepcted
+    }
+  }
+}